Rolling mill



c. P. FULLER ROLLING MILL F'iled Oct. 23. 1920 4 Sheets-Sheet l f@ ,V 4i )@@hif y ug. Mr, 1923.

1,464,792 C. P. FULLER ROLLING MILL Filed Oct. 23, 1920 4 Sheets-Sheet 27 f I I /e z/ 69 W/TA/fssfs ,13] 8 (f www Aug' n4,

C- P- FULLER ROLLING MILL 4 Sheets sheet 5 Filed Oct. 23, 1920 K m m wW/T/VESSES Aug. 14, 1923.

11,464,7@2 c. P. FULLER ROLLING MILL Filed Oct. 23, 1920 4 Sheets-Sheet4 FIE.

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CHA'NCEY E'. FULLER, 0F BELLE VERNON, PENNSYLVANIA.

ROLLING MXLJL.

Application led Uctober 28, 1920. Serial Ito. 418,965.

thickness, it is also adapted, by modification of the rolls for piercinga solid billet, and in fact for producing al finished tube from a solidbillet. It may also be used :for reducing the diameter of the tubewithout reducing its wall thickness.

The primary object of the invention isto provide a crossrolling mill forproducin finished tubes from hollow or solid billets in the one machine.

A further object is to provide a cross rolling mill which will, first,produce tubes that are smoother, straighter and more regular, with lessrelative expansion of diameter and less tendency to wall eccentricitythan can be produced on existing cross rolling mills or on groovedrolling mills without the subsequent use of reeling machines; and,second, to produce tubes more expeditiously, and with better powerelliciency than has heretofore been possible with cross rolling mills,or with combinations of grooved rolling mills and reeling machines.Other objects and advantages of the invention will be apparent from thedetailed description following.

ln the accompanying drawlngs Fig. 1 1s an end view of the mill, aportion being broken away to more clearly show the structure; Fig. 2 isa vertical section taken on the line 2 2, Fig. l, Fig. 3 is a plan viewot the mill; Fig. i isa plan view and Fig.

" 5 a side view showing 'the rolls in their relations'to each other andto the mandrel; Fig. 6 is a transverse central section through therolls, showing a tube lin the pass of the rolls; Fig. 7 is a detailedview of one form of roll and mandrel, shown in their oblique.

relation 'to each other and indicating" the nature of contact betweenthe roll and the billet, and also showing the changes eected on the tubewall between the roll and the f mandrel; and Fig. 8 shows a rectilineardevelopment of the line of contact el-g bei` tween a roll and the billetin relation to the mandrel.

in the drawing 1, 1 represent bed plates orfm1ll shoes, secured to thefoundation and serving as the support for the mill. 2 represents anannular frame which in radial cross section at any point issubstantially Hfshaped, havmg an outer annular ilanged portion 2a, aninner annular ilanged portion 2", and the connecting web portion 2c,which d is vcut away at points for mounting therein suitable gears ashereinafter described.

" lhis annular frame is provided with pro- ]ections or feet 3 which aresecured to the shoes 1 by suitable bolts as shown.

. rllhe rolls 4 have theusual necks or journals 5 carried in the bearingboxes 6, which constitute the ends of the roll carriers 7. Each rollcarrier is provided with an outg ward radial projection, of cylindricalshape 8, having therein a tapered socket into which the ta ered end 9 ofadjusting screw l0 is forced Ey the heavy bolt 11 extending axiallythrough the adjusting screw and into the roll carrier, as shown in Fig.2. By this construction 'the adjusting screw is made virtually integralwith the roll carrier, and serves as an outboard support to steady theroll carrier.

The projection 8 is slidable but non-rotatably secured, by means of key12, in the cylindrical sleeve 13, which is mounted in the inner annularflanged portion 2b of the main frame. The sleeve 13 is provided with asquare flange 14, which is engaged by two wedge kevs 15 and is therebyheld from turning. 7The Obliquity or feed angle of the rolls is thusmaintained, and can be varied by replacing keys 15 with other keys ofdifferent taper. y

Flach adjusting screw 10 is engaged by a threaded nut 17 which isrotatably mounted between bearing rings 18 located between the outer andinner annular portions 2a and 2b of the main frame. These nuts 17 areprovided on their peripheries with bevel gear teeth and are engaged by abevel ringgear 19 carried on six (or more) rolleribearing spools, 20,which serve as an eilillO `liquity or feed angles.

various sizes, without affecting their ob- One of t-he necks of eachroll is provided with a suitable extension, such as that shown at 29,for having connected thereto a suitable driving means, which may be ofany of the well known types now used for drivin cross or skew rolls. Thedriving means wi l be arranged to drive all three rolls-at the samespeed.

30 indicates the mandrel or plug lying in the pass of the rolls and heldin positionA by the usual mandrel bar 31 which will be mounted forwithdrawal from the roll pass in a manner well understood by thoseskilled in the art.

In the mill described, the three rolls are identical as to shape andsize, and all are positively driven at equal speeds. Correspondingpoints on each roll are all equidistant from the axis of the tube pass,and form the vertices of an equilateral triangle. The three planes inwhich lie the respective roll axes form the three faces of anequilateral triangular prism; and equal angles are formed between eachroll axis and the intersections of its respective plane with the planesof the two other roll axes. The angles thus measured will always be lessthan As described, this angle may be varied, but the condition ofequality ofangularity with respect to all three rolls will always bemaintained. A section through the mill transversely to the pass line atany point will "show the peripheries of the three rolls as equalellipses.

In consequence of the geometrical conditions just described, the actionsof the three rolls upon the billet are identical, the rolls themselvesforming the guides for the billet passing through the mill, and slidingorl friction guides being entirely eliminated. Furthermore, the billetis acted upon at three points spaced 120 lapart around its periphery,with the result that the tube is constrained against increase indiameter to a greater extent than with cross rolling mills having buttwo rolls.

The contour of the rolls may be varied, but for rerolling a hollowbillet it is preferred to use rolls which are approximately hyperboloidsof revolution, as illustrated in-v Fig. contact 7. Rolls of this contourhave a rolling with the surface of the billet along an approximatehelical element of considertact being shown 1n Fig. 7 by the line eg.This long contact results in forming smooth, substantially straighttubes. The hollow billet to be rolled comes into contact with the threerolls simultaneously at the points f (see Fig. V8) and is then pinchedinwardly, that is reduced in diameter, entering the feeding-in pass eawhich serves to grip the billet and force it into the reducing pass a-b.At a begins the reduction of the wall of the billet to the form shown inFig. 8. From b the contact of the rolls is parallel to the mandrel andis of very considerable length, thus giving a true reeling action' whichsmoothes the tube both inside and out. The tube being compressed.between the rolls and the mandrel at three equalized distances aroundthe periphery, when it leaves the parallel pass at g has a cross sectionwhich may be likened to a clover leaf, as shown in Fig. 6. Due to' theprogressive rolling of the tube, this form cannot persist, but changesto a substantially true circular form as soon as the tube is free fromthe rolls. To prevent this transition from resulting in a spiral markingon the tube, it is controlled by rounding the profile of the exit end ofthe rolls to a radius as shown at 1, Figs. 7 and 8.

The result of rolling a hollow billet on rolls of the characterdescribed is a tube which is smooth both inside and outside, is uniformand substantially circular in cross-section, and is not bent, scored, orgrooved as are tubes produced by the usual method in so-called plugrolls. Further more, the reeling or smoothing is effected in the samemill in which the reduction of wall Ythickness is effected, whereby isproduced in one machine a finished tube, requiring no further operationother than passing the same through the usual sizing rolls to gauge itto the exact diameter required.

As compared with prior cross rolling mills, the described mill has thefollowing peculiar characteristicst- No guides are required (except abell-mouth inlet) since the work is constrained and guided by the rollsalong three equi-spaced helices; the resultants of all working forcesare concurrent in the center line, or else are symmetrical about thecenter line, and therefore all forces are balanced except the necessaryrolling and feeding components; since all three rolls are driven (atequal speed) there is no pushing or pulling ofA the'metal over a guideor fricl tion roll; the provision of three helical lines of longcontact, instead of two, permits the use of very large feed angleswithout sacrifice of smoothness, thus combining to a considcrabe extentthe action of grooved rolls and cross rolls; the provision of threedriven rolls reduces slip, which results in higher speed through themill; constraining the tube radially at three points instead of tworesults in less expansion of diameter and greater increase of length,for the same reduction of wall thickness; the absence of frictionalguides, and the fact that all forces are cbncurrent or symmetricalresult in more efficient utilization of the power; and, finally, theprovision of hy erboloid rolls aving contact with the bi1 et for a greatlength along three twisted lines or approximate helices produces tubesthat are smooth, straight, and regular.

ln addition to the foregoing, the mill illustrated and described is ofsimple construction; the design permits of rugged proportioning of allparts; all adjustments are simple and easily made; and since this millembodies the functions not only of a rolling mill, but also those of areeler, there' is a great saving in oor space, size of crew,-1nvestment, and power required in the rolling of seamless tubes.

rlhe invention is not limited to the contour of the rolls illustrated,as this may be varied as found expedient in practice. The formillustrated however is well designed for producing smooth regular tubesfrom hollow billets.

. For reducing the diameter of a tube without reducing its wallthickness, the mandrel 30 may be omitted.

l claim:

l. ln a rolling mill the combination of three power driven cross rollsidentical in shape and size, set at th-ree uniform intervals around acentral pass and atv equal distances radially therefrom, and with theiraxes making angles greater than 45C to a plane normal tO the pass axis,'and having equal angles of Obliquity tO said pass, means for bodilyadjusting all said rolls equally toward and from the pass Withoutaltering their Obliquity, each roll being approximately a hyperboloid ofrevolution.

2. ln a rolling mill the combination Of three power driven cross rollsidentical in shape and size, set at three uniform intervals around acentral pass andat equal distances radially therefrom, and having equalangles of Obliquity to said pam, and means for bodily adjustin all threeof said rolls equally toward an away from the axis of the pass withoutaltering their Obliquity to the pass.

3. ln a tube rolling mill the combination of three power driven crossrolls identical in shape and size, set at three uniform intervals arounda central pass and at equal distances radially therefrom, and havingequal anglesl Of Obliquity to said pass, in combination with a plug ormandrel lying in the pass, said rolls and mandrel having contours toform, irst, a gripping or feeding-in pass between the rolls, second, awall reducing pass between the rolls and 'the mandrel, and, third, aparallel reeling pass between the rolls and mandrel.

4. ln a tube rolling mill the combination I of three power driven crossrolls identical in shape and size, set at three uniform intervals arounda central pass and at equal distances radially therefrom, and havingequal angles of Obliquity to said pass, in combination with a. plug Ormandrel lying in the pass, said rolls and mandrel having contours toform, first, a gripping or feeding-in pass between the rolls, second, awall reducing pass between the rolls `and the mandrel, third, a parallelreeling pass between the rolls and mandrel, and, fourth, a graduallydiverging exit Or rounding-up pass between the rolls.

5. In a rolling mill the combination of three power driven cross rollsidentical in shape and size, set at three uniform intervals around acentral pass and at equal distances radially therefrom, and having equalangles of Obliquity to said pass, means 'Or radially adjusting all threeof said rolls equally toward and away from the axis of the pass, andmeans for maintaining equal the Obliquity of each Of the three rollswith respect tO the pass, `the means for radially adJusting the rollsand the said maintaining means being independent of each other.

6. ln a rolling mill the combination of three power driven cross rollsidentical in shape and size, set at three uniform intervals around acentral pass and at equal distances radially therefrom, and having equalangles of Obliquity to said pass, each roll being mounted to have aswivel movement about a normal axis substantially midway of the lengthof its Working face, whereby its Obliquity to the pass can be varied,and means for maintaining equal the Obliquity of each of the three rollswith respect to the pass.

7. ln a rolling mill the combination of three power driven cross rollsidentical in shape and size, set at three uniform intervals around acentral pass and at equal distances radially therefrom, and having equalangles of Obliquity to said pass, each roll being approximately ahyperboloid of revolution, each roll being mounted to have a swivelmovement about a normal axis substantially midway Of the length Of itsworking face, whereby its Obliquity to the pass can be varied, and meansfor maintaining equal the Obliquity of each of the three rolls withrespect to the pass.

8. ln a rolling mill the combination of three power driven cross rollsidentical in shape and size, set at three uniform intervals varound acentral pass and at equal distances radially therefrom, and having equalangles of Obliquity to said pass, each roll being mounted to havea-swivel moveliti@ llll ' ment about a normal axis substantially midad]usting the three rolls equally toward orv away from the axis of thepass.

9. In a rolling mill the combination of l0 three power'driven crossrolls identical in shape and size, set at three uniform intervals arounda central pass and at equal distances radially therefrom, and havingequal angles of Obliquity tO said pass, each l5 roll being mounted tohave a swivelling movement about a. normal axis substantially midway ofthe length Of its working face, whereby its Obliquity to the pass may bevaried, means for retaining the rolls against swivelling movement, andmeans for bodily ,adjusting the three rolls equally toward or away fromthe axis of the pass, said retaining means and adjusting means beingindependent Of each other.

In testimony whereof, I have hereunto set 25 my hand.

CHAUNCEY P. FULLER. `Witnesses:

- R. C. THOMPSON,

W. A. MITOHEUR.

